Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02780585 2013-12-10
Tube Register for Indirect Heat Exchange
The present invention relates to a register for indirect heat exchange between
a utility
fluid, in particular a flue gas, containing an interfering component, and a
heat transfer fluid in
a heat exchanger, with a plurality of tubes for the passage of the heat
transfer fluid, wherein
the tubes are arranged in a plurality of tube layers as well as a plurality of
tube rows, wherein
the tube layers and the tube rows run transverse to one another and wherein
the tube layers
define a plurality of flow channels for the flow through of the utility fluid.
In addition the
invention relates to a heat exchanger with at least one register, and also a
use of the
register.
Registers of a heat exchanger comprise a plurality of tubes and are also
termed tube
bundles. The tubes form tube layers arranged parallel to one another. In this
way flow
channels for the flow through of the utility fluid are formed between the tube
layers.
Transverse to the tube layers the tubes form so-called tube rows, which are
likewise
arranged parallel to one another. In a register of a heat exchanger the
distances between
the tube rows are constant just like the distances between the tube layers. A
register is
therefore constructed symmetrically. The structure of a register, i.e. the
exact arrangement
of the tubes with respect to one another, is described by the so-called pitch.
If the tube rows and the tube layers are aligned perpendicular to one another,
this is
then described as a square pitch if the tube rows and the tube layers are
spaced equally far
from one another. If this is not the case, then it is described as a
rectangular pitch. For an
accurate definition of the arrangement of the tubes in addition to the nature
of the pitch the
distance of the tube mid-points between two tube rows and two tube layers is
also specified.
With a square pitch it is therefore sufficient to specify one distance.
If the tube rows and the tube layers are not aligned perpendicular to one
another,
then this is described as a triangular pitch. The tube mid-points of three
adjacent tubes then
lie at the corners of a triangle, which may be, but does not have to be, an
equilateral triangle.
If the lengths of the sides of such a triangle are known, then the arrangement
of the tubes in
the register is just as uniquely fixed as when in the case of square or
rectangular pitches the
lengths of the sides of a square or rectangle formed by the tube mid-points of
adjacent tubes
are specified. Within a register the distances relating to the respective
pitch do not alter.
Registers with a square pitch and a triangular pitch are diagrammatically
illustrated in Figs.
la and lb for the sake of clarity.
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CA 02780585 2013-12-10
Heat exchangers comprising such registers are known in various embodiments
from
practice and are referred to in particular as tube bundle heat exchangers. A
heat exchanger
can in this case comprise one or more registers. The heat exchangers are used
for heat
exchange between different fluids, which may be liquid or also gaseous. The
fluid flowing
through the register is hereinafter referred to as utility fluid, and the
fluid flowing through the
tubes of the register is referred to as heat transfer fluid.
If several heat exchangers are used in a process, then the utility fluid of a
heat
exchanger can if necessary be used as heat transfer fluid of another heat
exchanger. In this
case the utility fluid after leaving the one heat exchanger and before
entering the other heat
exchanger as heat transfer fluid is normally treated in a further process
stage, such as a
condensation or a separation of interfering components.
Heat exchangers are also known that operate in so-called cross-current. In
this case
the heat exchanger or at least a register is subdivided into two regions
separated from one
another, so that in the two regions different utility fluids flow around the
tubes of the register.
The flow directions of the utility fluids can in this case be opposite. The
heat transfer fluid
within the tubes of the register then in this case transports heat from one
region of the
register to the other region of the register, so that one utility fluid
transfers heat to the other
utility fluid. The utility fluids may be one and the same fluid stream at two
different points in
time during a technical process, for example for the processing, conditioning
and/or cleaning
of the fluid stream.
The heat exchangers and registers are used for example to cool or heat up a
utility
fluid in the form of a flue gas that is produced during combustion of a fuel.
For this purpose
the heat exchangers are for example integrated in a waste-gas purification
plant. Heat
exchangers designed to cool flue gases are for example connected in the form
of a gas
cooler upstream of a flue gas scrubber, whereas heat exchangers provided to
heat flue
gases can be connected downstream of a flue gas scrubber, in order to dry the
flue gas. In
this connection the temperature of the flue gas is raised to a higher level in
order to prevent
individual components condensing out in plant units connected downstream. Gas
coolers as
well as gas dryers can be provided in waste-gas purification plants.
Flue gases can, also like other media, contain a not inconsiderable amount of
interfering components. These interfering components are predominantly
particles, for
example in the form of dusts. Interfering components may however also be
liquids, such as
for example condensate or wash liquid entrained on discharge from an upstream
washer.
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CA 02780585 2013-12-10
The liquid is in this connection divided into a plurality of individual
droplets. The condensate,
especially in the treatment of flue gases, may be an acid or aqueous acidic
solution. In
addition the condensate can be introduced like other liquids and/or solids
into the heat
exchanger. The condensate can however also be formed first in the heat
exchanger or in at
least one register of the heat exchanger by a lowering of the temperature. In
general a
distinction is made in this case between the aggregate state of the
interfering component and
that of the utility fluid.
The interfering components in a utility fluid, such as for example a flue gas,
may be
homogeneous, for example of the same substance, or heterogeneous, composed of
different
substances.
The interfering components can coalesce in the heat exchanger, in particular
in at
least one of the registers of the heat exchanger, and collect there. Registers
that are
operated with utility fluids containing a relatively large concentration of
interfering
components should therefore be cleaned at regular intervals so that no
blocking of the
register occurs between individual tubes. Furthermore it can however also be
undesirable if
the interfering components are simply extracted with the utility fluid.
For the cleaning, a relatively large amount of rinse medium is often added to
the utility
fluid before entry to the register during operation, the rinse medium then
being entrained by
the flow of the utility fluid and carried through the register. This generally
occurs at more or
less regular, predetermined time intervals. The rinse medium can if necessary
also be
introduced uniformly distributed within the tube bundle of the heat exchanger.
The rinse
medium, which is generally water, should however in any case come into contact
with the
interfering components collecting in the register and remove these together
with the rinse
medium, in particular in the flow direction of the utility fluid, from the
register.
So that the register has as small a tendency as possible for interfering
components to
collect and can at the same time be thoroughly cleaned, the register is
constructed so that
the utility fluid has a high flow velocity between the tube layers, which are
aligned in a regular
manner parallel to the outflow direction of the utility fluid. This is
achieved in particular if the
registers are constructed of tubes with relatively large diameters, which for
this purpose are
arranged at large distances from one another. In the end broad flow channels
are thereby
formed between the tube layers, which offer a low flow resistance to the
utility fluid and
through which utility fluid can thus rapidly flow.
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CA 02780585 2013-12-10
Nevertheless it has been found in practice that the interfering components can
collect
to a large extent in the register, which can lead to the partial blockage or
clogging of the
register, for example in flow shadows between the tubes of a tube layer. This
then means for
example that continuously operating plants have to be shut down prematurely in
order to
service the register or clean it manually. This often leads in the case of
hardening interfering
components to damage to the tubes and/or to their corrosion protection due to
the difficult
and in some cases mechanical cleaning. This in the end leads to undesirable
tube failures.
The object of the present invention is therefore to design and develop a
register and a
heat exchanger of the type mentioned in the introduction, so that when
operating with utility
fluids containing large amounts of interfering components, such as for example
flue gases,
the tendency to contamination and blockage is reduced and in this way longer
service lives
can be achieved in continuous operation.
The aforementioned object is achieved according to the invention with a
register, in
that in at least one tube row there is provided at least one flow channel with
a small channel
width and also at least one flow channel with a large channel width, and/or
that in at least
one tube row there is provided at least one flow channel with a narrow section
defined by a
small channel width and also a wide section defined by a large channel width,
and that the
large channel width is designed to produce a high flow velocity of the utility
fluid and the
small channel width is designed to produce a low flow velocity of the utility
fluid.
The present invention has recognised that, contrary to the previous teaching
regarding the design of heat exchange registers, the symmetrical arrangement
of the tubes
in the registers is disadvantageous as regards an undesirable accumulation of
interfering
components in continuous operation.
On the basis of this knowledge the invention has accordingly dispensed with an
extremely symmetrical structure of the register and has created a register
that is to some
extent intentionally constructed asymmetrically. This intentional asymmetry is
created by
providing in the register flow channels with considerably different channel
widths. A
considerably different channel width means in this connection that the channel
widths
noticeably differ from one another, and that the flow resistances in the flow
channels
significantly differ from one another. The difference between the channel
widths is in this
connection dependent on the utility fluid and the process conditions and
accordingly cannot
be quantified exactly. Alternatively however it may also be envisaged that at
least one flow
channel has different sections with different channel widths, the differences
being significant
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CA 02780585 2013-12-10
, .
in the sense described hereinbefore. If necessary a combination of the
previously described
alternatives is also possible.
Large channel widths mean that the flow resistance counteracting the utility
fluid
decreases and at the same time the flow velocity of the utility fluid
increases. In this
comparison it is assumed of course that there is a constant pressure loss of
the utility fluid
stream when flowing through the register. With smaIl channel widths the flow
resistance
increases however, so that in these regions of the register a lower flow
velocity prevails.
According to the invention regions with different flow velocities in the
register are therefore
produced completely intentionally.
A small channel width is in this connection so small that the utility fluid
flow is retarded
to such an extent that this leads to a noticeable settling of interfering
components entrained
by the utility fluid. In the regions with a large channel width the flow
velocity is on the other
hand so high that the retardation of the utility fluid flow in the regions of
small channel width
can be compensated. This preferably means that, for a constant pressure loss,
the same
volume flow of utility fluid flows through the register as in a symmetrical
arrangement of the
tubes in the register. Depending on the available pressure loss, there is not
in this case an
exact observance of the aforementioned connection. In addition it is assumed
with this
pressure loss observation that the register is not contaminated.
Otherwise, with a
conventional register, on account of the higher depositions of interfering
components the
utility fluid flow can for the same pressure loss be significantly less than
in the case of the
previously described register.
The large channel width can, depending on the specific application, preferably
be
more than 1.10, more than 1.25, more than 1.5 more than 2.0, more than 2.5 or
more than
3.0 times as large as the small channel width. In principle therefore a
noticeable difference
between the large and small channel widths is preferred. At the same time or
alternatively it
can however be a hindrance as regards the flow distribution within the
register if the
differences between the large channel width and the small channel width are
too significant,
so that in certain circumstances non-active dead zones can be formed in which
no flow
occurs. With differences that are too large as regards the channel widths,
then alternatively
or in addition the heat-exchange surface as the sum of the jacket surfaces of
the tubes of the
register can be greatly reduced, which can have an unfavourable effect on the
heat to be
exchanged per volume of the register. The large channel width should therefore
if necessary
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CA 02780585 2013-12-10
not be more than 5, not more than 4, not more than 3 or not more than 2 times
as wide as
the small channel width.
Differently dimensioned large channel widths and/or differently dimensioned
small
channel widths may also be provided within a register. In this way a high
degree of
asymmetry and thus a large number of different flow states are created within
the at least
one register of a heat exchanger.
The above details regarding the dimensions of large and small channel widths
also
applies to flow channels of individual tube rows, in which there is a constant
channel width
between two adjacent tubes, as well as to those tube rows in which between two
adjacent
rows there is over some sections a large channel width and over other sections
a small
channel width.
If necessary regions can be provided in the register in which the flow of the
utility fluid
almost comes to a stop. This is not necessarily the case however. The flow
velocity in these
quiet zones should however be reduced to such an extent that the interfering
components
and/or rinse media added for cleaning purposes can noticeably settle under the
action of
gravity. Of course, the flow should also not completely come to a stop since
then also no
flow components would flow any longer into the quiet zones and there sink to
the bottom.
Also, the flow velocity should not be reduced to such an extent that the flow
channels
become too wide in the regions with a large channel width, since this can have
a negative
effect on the heat exchanger. The flow velocity in the regions with a large
channel width
should also not have to be increased so significantly in order to be able to
still transport the
necessary volume stream through the register, that this is offset by a
markedly increased
pressure loss in this case.
In order that the interfering components in the quiet zones in the register,
i.e. in the
region of small channel widths, can sink under the action of gravity,
interfering components
are removed from the utility fluid. The interfering components can in this
connection sink
completely to the bottom, and the deposited interfering components can
preferably be
removed in any suitable way and means in order to prevent an accumulation. In
particular a
partial stream of the interfering components flowing into the register will
sink under the action
of gravity and be deposited on the floor of the register, while the other part
is removed
together with the utility fluid from the register in the flow direction of the
utility fluid.
If the interfering components are particles or condensate, it may be
sufficient if these
interfering components sink to some extent in quiet zones and re-enter, at a
lower level,
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CA 02780585 2013-12-10
zones of higher flow velocity, so as then to leave the register together with
the utility fluid
stream. A blockage of the register can thereby if necessary already be
avoided.
Corresponding heat exchangers are preferably designed as gas coolers. If the
heat
exchanger is designed as a gas dryer, in which the utility fluid is heated,
and if the interfering
components are droplets introduced with the utility fluid, which for example
are entrained
from an upstream gas scrubber or dry separator, it is preferred to draw the
interfering
components substantially completely to the bottom and in this way remove them
smoothly
from the utility fluid stream after the latter enters the register. This is
energetically preferred,
since the droplets deposited on the bottom do not have to be evaporated in the
register in
order to achieve the necessary dryness of the utility fluid when leaving the
register. The
necessary dryness of the utility fluid is then achieved if its temperature
lies sufficiently above
the dew point and/or the utility fluid in any case no longer contains any
droplets.
With tube bundle heat exchangers of the prior art the proportion of the
interfering
components that is not extracted again with the utility gas flow accumulates
in at least one
register of the heat exchanger, for example in the form of adhering particles
or
agglomerations, which necessitates a premature shutdown and cleaning of the
register.
On account of the fact that with the register according to the invention high
flow
velocities of the utility fluid can be achieved in the wide sections with a
larger channel width,
this preferably leads to turbulences within the heat exchanger, which in the
end can in turn
cause interfering components from the regions of higher flow velocity to reach
regions of
slower flow velocity and there sink to the bottom. Interfering components can
also pass from
the rapidly flowing utility fluid from quiet zone to quiet zone and thereby
sink to the bottom in
stages or only partially sink, and can for example be removed at a deeper
point from the
register via channels of large channel width.
Interfering components are understood to mean the plurality of particles
and/or
droplets entrained by the utility fluid. The interfering components may
therefore have as
desired a homogeneous or a non-homogeneous composition, wherein the
interfering
components can also consist of different materials and if necessary have
different states of
aggregation.
The heat transfer fluid flowing through the tubes may if necessary be a so-
called heat
transfer medium, specially provided for heat transport. In particular water
and oils are
suitable for this purpose. Alternatively the heat transfer fluid may however
also be a process
medium that preferably, just like the utility fluid, is likewise present in
any case and preferably
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CA 02780585 2013-12-10
has to be heated or cooled in any case. The heat transfer fluid can for
example also be a
flue gas. Heat transfer fluid and utility fluid may be gaseous and/or liquid
as desired.
Preferably the utility fluid is a flue gas, furthermore preferably a flue gas
that has to be cooled
or heated.
The register serves for indirect heat exchange, since the heat transfer fluid
and the
utility fluid do not come into direct contact with one another, but the heat
is simply transferred
through the tube walls.
The register comprises a plurality of tube layers and tube rows, wherein the
tubes of
one tube row are part of different tube layers, and vice versa. In this
connection the tube
layers extend substantially in the flow direction of the utility fluid, while
the tube rows are
aligned inclined, optionally transverse, to the flow direction of the utility
fluid.
The tubes of at least one tube layer can in this connection be arranged in the
flow
direction of the utility fluid in each case flush behind one another or
however also displaced
with respect to one another, while the tubes of at least one tube row are
arranged transverse
to the flow direction of the utility fluid in each case flush behind one
another or however also
displaced with respect to one another.
The width of a flow channel is in this connection always determined in a tube
row,
and specifically is the distance between two adjacent tubes bordering the flow
channel. In
this way the channel with of at least one flow channel of a register can vary
from tube row to
tube row, but can also remain constant. In the case where the flow channel in
at least one
tube row contains sections of different channel widths, i.e. narrow and wide
sections, the
narrow and wide sections can be arranged uniformly behind one another from
tube row to
tube row in the flow direction of the utility fluid. It may however also be
envisaged that a
narrow section in the flow direction follows a wider section in the following
tube row, or that
the channel width of the narrow and of the wide sections varies in successive
tube rows as
well as also in one and the same tube row.
It is understood that when at least one tube row, tube layer or flow channel
is
discussed herein, this can also mean an arbitrary plurality of tube rows, tube
layers and/or
flow channels. For example, this can be an overwhelming majority whose
proportion
exceeds 50%. However, all or substantially all tube rows, tube layers and/or
flow channels
may also be intended.
In a first design of the register a simple fabrication and a simple layout of
the register
may be provided, in which at least individual flow channels of the register
have a constant
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CA 02780585 2013-12-10
channel width in tube rows of the register following one another in the flow
direction of the
utility fluid. The channel width of a uniform flow channel therefore does not
alter in the
transition from one tube row to the next tube row in the flow direction. In
other words, the
register constructed in this way has flow channels that are formed identically
in successive
tube rows. In this connection these flow channels can have a constant but also
a varying
channel width in the direction of the respective tubes. Preferably, since it
is easy to produce,
at least one flow channel has a constant channel width along all tube rows of
the register.
The channel width of the flow channel therefore does not alter along the flow
direction of the
utility liquid. At the same time however the corresponding flow channel does
not necessarily
have to have a constant channel width in the direction of the tubes, but can
possibly have
alternately narrow as well as wide sections with correspondingly small and
large channel
widths.
To simplify the fixing of the tubes of the register, alternatively or addition
it may be
envisaged that in at least one tube row each tube is fixed to a retaining
element that is
formed in the shape of a rod and extends substantially along the tube layers.
The influence
on the flow can thus be minimised. In addition the rod-shaped retaining
elements of a tube
interfere only minimally in the settling of the interfering components.
If necessary the at least one retaining element may also be in the form of a
grid, or
may be bent particularly around tubes adjacent to the retaining element. The
retaining
elements interfere with the settling of the interfering components as little
as possible and if
necessary in addition allow a certain mobility of the tubes, especially if
these are flexibly
arranged. In general metals, ceramics or plastics are suitable materials for
the production of
the retaining element, and the metals may have a corrosion protection that is
formed if
necessary by a plastics casing. Fluorinated plastics in particular are
suitable as plastics
material for the retaining element or the casing.
A structurally simple and also effective possibility exists if in at least one
tube row in
each case a retaining element is provided in every second flow channel. The
tubes adjacent
to each retaining element are then fixed to the latter, more specifically
preferably at the side.
Alternatively it may however also be envisaged that exactly one tube layer is
fixed on
at least one retaining element of the register, while exactly two adjacent
tube layers are fixed
on at least one other retaining element. This is convenient in particular when
using tubes of
different diameters in at least one tube row. Then for example alternately one
tube layer with
tubes of a large diameter can be secured to its own retaining element, while
adjacent thereto
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CA 02780585 2013-12-10
two tube layers with tubes of smaller diameter are fixed to a common retaining
element
arranged between the tube layers.
In this case it is particularly advantageous for the free settling of the
interfering
components if the retaining elements run substantially laterally to the tube
layers held by the
retaining element.
In addition to the fixing the retaining elements can also serve for the
positioning of the
tubes of at least one tube row or the whole register. For this, it may be
envisaged that the
retaining elements between the tubes of at least one tube row located on the
retaining
elements have spacers for spacing the tubes located on the said retaining
elements.
Alternatively or in addition it may however also be envisaged that the
retaining elements are
formed directly as spacers. They then have between the tubes to be spaced
apart in each
case a width that corresponds to the desired interspacing of the tubes,
without the need of a
further structural part for this purpose.
So that the retaining elements do not interfere too strongly in the flow of
the utility
fluid through the register, it is advantageous if the retaining elements are
arranged either in
flow channels with a small channel width and/or in narrow sections of the
respective flow
channel of at least one tube row. In addition the tubes in these flow channels
and/or sections
in any case have a small distance to the mutually adjacent tubes, so that a
fixing of the tubes
can be achieved with a saving in material. In this case the retaining elements
interfere only
slightly in the settling of interfering components in quiet zones, since the
retaining elements
are arranged laterally on the tubes.
In this connection it is possible for the retaining elements to be provided
along the
whole respective tube layers in each case in flow channels of small channel
width and/or
narrow sections of the flow channels. In this way the described advantages are
achieved in
all successive tube rows of the register. Alternatively or in addition it is
preferred for
structural reasons if the retaining elements are always provided in every
second flow
channel. This is sufficient in order to fix all tubes of a tube row and thus
of the register as a
whole.
So that the at least one retaining element influences the settling of
interfering
components even less, the retaining element can also be arranged in the flow
channels with
a large channel width and/or in wide sections. Interfering components that
settle on a
retaining element are then more easily removed and do not accumulate so
markedly during
operation. Preferably the retaining element is then aligned along a flow
channel with a wide
CA 02780585 2013-12-10
channel width and extends in this flow channel along a tube layer bordering
the flow channel.
In this case retaining sections of the retaining element can thereby then be
provided that join
the tubes of this tube layer to the retaining element.
If despite the formation of quiet zones and zones of increased flow velocity
of the
utility fluid through the arrangement of the tubes of the register between one
another it is still
necessary to clean the register in operation, a rinse line for feeding rinse
medium can be
provided in at least one tube row in at least one flow channel with a small
channel width or in
a narrow section. In this connection the rinse line extends substantially in
the direction of the
tube layers and/or in the direction of the flow channels, which is preferably
in the same
direction.
It is particularly convenient for the cleaning of the register if a rinse line
is provided in
at least one tube row in each flow channel with a small channel width. In
addition or
alternatively, in flow channels with a varying channel width on a common plane
a rinse line
can in each case be provided in the narrow sections of the flow channels. Wide
sections of
flow channels of the register can if necessary manage without a rinse line.
So that all regions of the register, in particular the quiet zones of the
register, can be
reached equally by the rinse liquid, it is advantageous to provide in at least
one tube row a
rinse line in every second flow channel. This applies in particular if the in
each case at least
second flow channel has a small channel width and varying channel width.
In addition to supplying rinse liquid the rinse lines can be designed as
spacers for
spacing the rinse line of adjacent tubes of the at least one tube row. This is
achieved in a
structurally simple manner if the rinse lines have a diameter that corresponds
to the preferred
interspacing of the adjacent tubes in the region of the respective rinse line.
The rinse lines can in addition be arranged in each case in the flow channel
of small
channel width and/or in the narrow section of the flow channel, since in this
way the rinse
liquid can be fed specifically to the quiet zones, the flow in the flow
channels of large channel
widths is not adversely affected, and the tubes in the said flow channels
and/or in the said
sections can in any case lie close to one another.
In order to minimise the structural effort involved in the fabrication of the
register, at
least one retaining element can be designed at the same time as a rinse line,
or vice versa.
In this connection it is convenient if the at least one retaining element has
a substantially
closed profile, through which the rinse medium can flow, the rinse medium
being able to
leave the corresponding profile through a series of openings.
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CA 02780585 2013-12-10
Alternatively or in addition it may be envisaged that at least one tube layer
is at least
in sections aligned slanting and/or bent in relation to the inflow direction
of the utility fluid
through the register. As a result the free flow channel for the utility fluid
is inclined relative to
the inflow direction of the register. The utility fluid as such is thereby
preferably deflected,
and specifically in the direction of the free flow channel. The interfering
components, which
preferably have a higher density, are however subjected greater inertial
influence and are
deflected less strongly or hardly at all. In this connection the tubes of a
tube layer are
preferably arranged displaced with respect to one another so that the
interfering components
if necessary impact in the further course of the flow against a tube of a
further tube row
arranged behind in the flow direction, or preferably against a tube arranged
further behind in
the flow direction, of a tube layer defining the flow channel. The flow
velocity of the utility
fluid is reduced directly at the tubes, so that the interfering components
impacting against a
tube can more readily sink to the bottom under the force of gravity.
Preferably the tubes arranged behind one another in the flow direction are in
each
case displaced only by a part of the channel width. The tubes are then not set
facing one
another at gaps, which is more unfavourable from the point of view of flow,
but always stand
further in the flow channel defined by the front tube row. The flow channel
can then be
widened to the same or a similar extent on the other side, so that the flow
channel overall
has substantially a constant channel width along at least one tube layer. The
flow channel is
however inclined somewhat to the inflow direction of the register. This
arrangement has the
effect that interfering components entrained by the utility fluid, in
particular in the form of
droplets, flow through the register without any problem, but impact with a
fairly high degree of
probability against one of the tubes of the register, which projects into the
flow channel in the
inflow direction.
So that corresponding registers can be produced simply and in addition fluid
can flow
through them relatively uniformly, it may be envisaged that at least two tube
layers form
between them a flow channel with an opening on the inlet side and an opening
on the outlet
side for the utility fluid, in such a way that the opening on the inlet side
in the inflow direction
of the utility fluid in relation to the register does not overlap the opening
on the outlet side.
An interfering component, for example in the form of a droplet, then cannot,
or in any case
scarcely, be carried through this rectilinearly in the inflow direction of the
register. Instead
there is a very high probability that the droplets will strike against tubes
of one of the tube
layers and will accordingly be deposited. Thus, a removal of for example
entrained liquid
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CA 02780585 2013-12-10
from the utility fluid is possible. Preferably the opening on the inlet side
is the channel width
of the flow channel formed in the flow direction of the utility fluid in the
foremost tube row,
while the opening on the outlet side is similarly the channel width of the
flow channel of the
rearmost tube row. Alternatively, the terms inlet side and outlet side instead
of referring to
the register as such can also refer to a partial region of the register, so
that further tubes or
tube rows can be allocated on the inlet side and/or outlet side.
It may be envisaged that flow channels with constant channel widths are
arranged in
at least one tube row. This can be accomplished easily and cost-effectively,
especially with
rectilinear tubes. Nevertheless if necessary a asymmetry can be created in a
tube row by
providing there flow channels that have varying channel widths along the
longitudinal length
of the tubes, i.e. preferably wide sections and narrow sections.
The register in principle becomes even simpler and more cost-effective if at
least the
flow channels situated in a tube row have in each case a constant channel
width. The
channel width is in this connection constant in the direction of the
longitudinal length of the
tubes. Preferably the channel widths in all tube rows of the register are
constant. This
allows a very simple and thus cost-effective construction of the register, the
tubes being
formed in particular rectilinearly.
Alternatively or in addition it may be envisaged that in at least one tube row
there is
arranged at least one flow channel with alternating narrow sections and broad
sections. This
enables a register to be constructed for example with the desired asymmetry by
a
combination of flow channels with a constant channel width and flow channels
with a varying
channel width in one tube row but also however in different tube rows. The
flow channels
are in this case understandably provided in the longitudinal length of the
tubes with a
constant or varying channel width.
So that the construction of the register does not have to be too complicated
despite
the desired asymmetry of the register, in at least one tube row all flow
channels have in each
case varying channel widths, wherein in each individual flow channel of the
tube row narrow
sections alternate with wide sections.
A further, possibly additional, way of forming an asymmetry in the register
without
having to construct and configure the register in a random and therefore
complicated
manner, could be to arrange next to one another in at least one tube row in a
direction
perpendicular to the tubes of the tube row narrow sections and wide sections
of adjacent flow
channels alternating with one another. This means that in the at least one
tube row there is
13
CA 02780585 2013-12-10
provided at least one flow channel that has a wide section on a specific plane
perpendicular
to the tubes, while the adjacent flow channel on this plane has a narrow
section.
At the same time or as an alternative it may be envisaged that individual flow
channels of the register in successive tube rows in the flow direction of the
utility fluid have
alternately a small channel width as well as a large channel width and/or a
narrow section as
well as a wide section of the flow channels. The channel width of a same flow
channel
changes therefore at the transition from one tube row to the next tube row in
the flow
direction. In other words, the register constructed in this way has flow
channels that in
successive tube rows have a shape that varies, and particularly preferably
alternates, in the
flow direction of the utility fluid. The shape of the flow channels thus
varies and allows an
asymmetric structure of the register, which at the same time can therefore
easily be
produced and calculated for the purposes of the layout.
One possibility of combining regions with a large channel width and a narrow
channel
width in one register is if at least individual tubes of at least one tube row
are over some
regions part of a first row layer and over other regions part of a second row
layer. The
corresponding tubes therefore run in sections in one tube layer and in
sections in at least one
further tube layer. This is achieved for example if adjacent tubes of a tube
row are crossed
with one another, wherein one tube is led from one tube layer of the tube row
to the adjacent
other tube layer of the tube row, while the adjacent tube is led from the
adjacent other layer
to the one tube layer. A corresponding crossover of the tubes can be
implemented singly but
also multiply in a tube row in a flow channel.
It is understood of course that the tubes of arbitrary tube layers in a tube
row can be
crossed with one another or also arbitrary tubes of a tube layer can be
crossed with one
another. It is also possible for tubes to cross one another that belong on the
one hand to
different tube rows and on the other hand to different tube layers. For the
sake of simplicity it
is however envisaged that adjacent tubes of a tube row run in sections in
immediately
adjacent tube layers of the tube row.
A simpler, more regular but also non-symmetrical structure of the register can
be
achieved if a flow channel defined by a first tube layer and a second tube
layer has in at least
one tube row a plurality of narrow sections and/or wide sections. In other
words, in at least
one flow channel between two tubes crossed over one another in at least one
tube row along
the longitudinal direction of the tubes there are provided exclusively wide
sections,
exclusively narrow sections or alternately wide and narrow sections, and
preferably
14
CA 02780585 2013-12-10
alternating sections. Exclusively narrow sections occur when the tubes of the
two tube
layers of a tube row defining the flow channel always cross one another
alternately along the
longitudinal direction of the tubes and only narrow flow cross-sections remain
free between
the crossover points. The wide sections are then preferably provided in
adjacent flow
channels of the same tube row. For this purpose it is then if necessary
sufficient if the
adjacent tubes of the tube row run rectilinearly, since the crossed tubes
ensure that the
thereby formed channel width of the adjacent flow channel varies.
In this way an asymmetry of the register can be produced in a simple way in
that at
least individual tubes of at least one tube row cross one another, preferably
multiply, along
the longitudinal length of the tubes.
A relatively regular structure of the register with a large number of wide
sections as
well as narrow sections is then obtained if substantially all tubes of at
least one tube row are
crossed, preferably multiply, with in each case neighbouring tubes along the
longitudinal
length of the respective tubes.
The crossover points of tubes crossed tubes with one another can in this
connection
lie on the same planes perpendicular to the longitudinal length of the tubes,
like the
crossover points of the adjacent tubes crossed with one another. Alternatively
or in addition,
for example in a further tube row, the crossover points of tubes crossed with
one another can
lie on a first row of planes, while the crossover points of the adjacent tubes
of the tube row lie
on a second row of planes, which are likewise aligned perpendicular to the
longitudinal
length of the tubes. In this case planes of the first row of planes and planes
of the second
row of planes can always be provided alternately in the longitudinal length of
the tubes,
wherein in a particularly regular, even if not symmetrical, register
arrangement the distances
between the individual planes are always identical.
Preferably, since it is easier to
implement, the crossover points of in each case two tubes crossed with one
another always
lie alternately on the first row of planes and on the second row of planes.
Adjacent crossed
tubes are therefore always arranged alternately in the longitudinal direction
of the tubes and
displaced with respect to one another by the interspacing of the planes of
different rows.
Not all tubes of a tube row have to be crossed with one another, and it may be
simpler for the production of the register if rectilinearly formed tubes are
provided adjoining
crossed tubes in a common tube row, which then form with the crossed tubes a
flow channel
in the tube row, which has varying channel widths, so that if necessary narrow
sections and
wide sections can alternate.
CA 02780585 2013-12-10
Varying channel widths and thus an intentional asymmetry of the register can
be
achieved structurally in a particularly simple manner if in at least one tube
row and/or in at
least one tube layer tubes are provided having noticeably different tube
diameters. In this
case in the at least one tube row or tube layer tubes with different diameters
can be arranged
alternately and in such a way with respect to one another that the flow
channels with different
channel widths are produced therefrom. It may however also be envisaged that
each tube of
at least one tube row with a larger diameter is arranged adjacent to in each
case two tubes of
the at least one tube row with a smaller diameter. In other words, in a tube
row if necessary
two thin tubes are followed by a thick tube, which is then followed in turn by
two thin tubes,
and so on.
In this connection exclusively tubes with an identical tube diameter may be
provided
in at least one tube layer. In the end the register can thus be composed
simply of tube layers
with the same type of tubes.
Irrespective of the arrangement of the tubes of the register, it is preferred
if the tubes
are made of a plastics material, preferably a fluorinated plastics, in
particular perfluoroalkoxy
(PEA). In this way a high resistance to corrosive media is achieved.
Alternatively or in
addition the tubes can be made of metal, preferably of a suitably resistant
metal, in particular
of a corrosion-resistant metal.
Furthermore it may be desirable if the tubes are designed to be flexible, so
that the
tubes can easily be arranged in the desired alignment with respect to one
another. This is
especially the case if individual tubes are to be crossed with one another.
The necessary
flexibility can be ensured without any problem by the aforementioned plastics
material of the
tubes.
Under certain conditions the register can however also include flexible as
well as rigid
tubes. This is convenient for example if the rigid tubes are to contribute to
the stability of the
register. When using tubes of different diameters it may for example be
envisaged that the
tubes of larger diameter are rigid, while the tubes of smaller diameter are
flexible.
Alternatively or in addition it is possible for rectilinear tubes of a
register to be rigid and for
the bent tubes of the same register to be flexible. It may however also be
envisaged that the
flexible tubes are made of a plastics material and the rigid tubes of metal.
In order to reduce the fluid sound occurring in the register, the tubes of at
least two
adjacent tube layers with mutually displaced tubes can be brought very close
to one another
in a simple manner, if necessary even overlapping. Then, if at all, only very
narrow gaps
16
CA 02780585 2013-12-10
transverse to the flow direction of the utility fluid remain between the
corresponding tubes. In
the end the tubes jointly form a so-called tube disc, which to a large extent
reflects the sound
waves. Alternatively or in addition at least one corresponding tube disc can
be provided by
bringing the tubes of at least one tube layer so close to one another that no,
or only very
slight, gaps remain between the tubes of this tube layer. In order to achieve
this, then in the
at least one tube layer either the number of tubes is significantly increased
compared to
other tube layers or their diameter is significantly increased compared to
other tubes of the
register. In this connection it may alternatively or additionally be
advantageous to cross
adjacent tubes of the at least one tube layer with one another in order to
obtain in this way a
stabilised "wickerwork" of tubes or a tube disc of tubes crossed with one
another. This is
feasible especially if the tubes of the tube register are flexible, and are
made for example of
plastics material. Alternatively in the case where the tubes of the register
are formed
substantially flexible, also the tubes of the at least one tube layer for
reflecting the sound can
be formed rigid, for example made of metal.
It is particularly preferred to provide corresponding tube layers formed in
the manner
of a tube disc on or adjacent to both edges of the register. Also, such a tube
layer may
additionally or alternatively be advantageous for example in the middle of the
register. Two
to six tube discs might well be preferred in the normal case, in order to
achieve a significant
sound reduction due to reflection of the fluid sound.
In a first preferred modification of the heat exchanger it is envisaged that
in the flow
direction of the utility fluid a barrier aligned transverse to the flow
direction is provided in front
of the lower end of the register in the direction of gravity, in order to
protect the tubes against
abrasion caused by interfering components entrained by the utility fluid. The
interfering
components are in this connection in particular particles, such as dust or the
like.
The barrier is in this connection preferably installed where local peaks in
the
concentration of interfering components occur. On account of the influence of
gravity on the
interfering components this location is generally on the floor of the heat
exchanger. The
barrier is therefore preferably provided at the lower end of the register in
the direction of
gravity.
In this connection it may be envisaged that the barrier forms a gap with the
floor of
the heat exchanger. The utility fluid flows with increased velocity through
this gap and can
thus entrain interfering components collecting at the bottom and/or that have
preferably sunk
towards the bottom in the quiet zones, and in this way remove them from the
heat
17
CA 02780585 2013-12-10
exchanger. This in the end leads to a removal with the utility fluid. This is
different however
from the known removal in that the removal does not take place with the core
flow of the
utility fluid, but with an edge flow of the utility fluid close to the bottom.
In this way the
interfering components can be transferred without any problem directly to the
sump of a
downstream-connected plant unit, such as for example a washer.
It is convenient in this connection if the height of the free gap corresponds
at most to
about the minimum interspacing between the end of the register and the floor
of the heat
exchanger, so that the lower end of the register is not subjected to increased
abrasion by the
interfering components.
On account of the reduced structural effort involved in installing the
register in the
heat exchanger and replacing the register, the register is preferably designed
as a
suspended U-shaped tubular heat exchanger register with tube bends at the
lower end of the
register in the direction of gravity.
It may then also be envisaged that in the region of the tube bends in at least
one tube
row the channel width is a maximum at least in a flow channel with a large
channel width. In
other words, this at least one flow channel widens out downwardly in order to
improve the
removal of interfering components from the register, even if this has the
result that the
channel width of adjacent flow channels becomes correspondingly smaller, so
that the width
of the register overall can remain constant.
For the aforementioned reasons it may be advantageous if individual flow
channels in
the region of the tube bends have such a large channel width that as a result
in at least one
tube row the channel width is essentially zero at least in a flow channel with
a small channel
width. The corresponding adjacent tubes of the at least one tube row can in
this case lie
preferably almost abutting one another.
The afore-described structural features of the register of the heat exchanger
can in
principle be combined with one another in any arbitrary way. This applies in
particular also to
the various described ways in which a register of a heat exchanger can differ
from a
symmetrical construction. Use may therefore be made of different types of an
asymmetric
design and/or different dimensions of a specific asymmetric design for example
in various
tube rows and/or tube layers of different types. Use could also be made of
such different
designs in one and the same tube row and/or tube layer. In order to keep the
complexity low
as regards the production and design of the register, it is nevertheless
convenient if in each
case in one tube row and/or one tube layer use is made in each case of only
one design,
18
CA 02780585 2013-12-10
. =
which overall leads to an asymmetric structure of the register. In other
words, different tube
layers and/or tube rows may then differ structurally from one another.
The afore-described register is on account of its design particularly suitable
for
heating and/or cooling a gas, such as in particular a flue gas, containing
interfering
components. In this connection the interfering components may be particles,
condensate
and/or entrained liquid. The effects of the register are accordingly
manifested in particular if
the register is connected upstream and/or downstream of a flue gas scrubber.
The flue gas
is then heated and/or cooled.
The invention is described in more detail hereinafter with the aid of a
drawing simply
illustrating exemplary embodiments, in which:
Fig. 1a shows a register of a tube bundle heat exchanger of the prior art with
a square
distribution, in a sectional view perpendicular to the tubes of the tube
bundle,
Fig. 1bshows a register of a tube bundle heat exchanger of the prior art with
a
triangular distribution in a sectional view perpendicular to the tubes of the
tube bundle,
Fig. 2 shows a detail of a first embodiment of a register according to the
invention in
a direction parallel to the flow direction of the utility fluid,
Fig. 3 shows the detail of the register of Fig. 2 in a sectional view along
the plane II-II
of Fig. 2,
Fig. 4 shows a further detail of the register of Fig. 2 in a direction
parallel to the flow
direction of the utility fluid,
Fig. 5 shows a detail of a second embodiment of the register according to the
invention in a sectional representation according to Fig. 3,
Fig. 6 shows a detail of a third embodiment of the register according to the
invention
in a sectional representation according to Fig. 3,
Fig. 7 shows a detail of a fourth embodiment of the register according to the
invention in a viewing parallel to the flow direction of the utility fluid,
Fig. 8 shows a detail of a fifth embodiment of the register according to the
invention
in a viewing parallel to the flow direction of the utility fluid,
Fig. 9 shows a detail of a sixth embodiment of the register according to the
invention
in a viewing direction parallel to the flow direction of the fluid,
Fig. 10shows the floor region of a first embodiment of the heat exchanger
according
to the invention in a viewing direction parallel to the flow direction of the
utility fluid, and
19
CA 02780585 2013-12-10
Fig. 11 shows the floor region of the heat exchanger of Fig. 10 in a sectional
representation along the plane IX-IX of Fig. 10.
Conventional types of a register that are known from the prior art are
illustrated in
Figs. la and lb. The tube bundle of a register of a heat exchanger illustrated
in Fig. 1 a has
a square distribution. The tube mid-points of two adjacent tubes R of a tube
row RR and of
two tubes arranged flush therewith then form the corners of a square. In other
words, in
such a register the adjacent tubes R of a tube row RR as well as adjacent
tubes R of a tube
layer RL are in each case arranged at the same distance from one another. If
this distance
between the tube layers and the tube rows were different, this would not be a
square
distribution but a rectangular distribution. In this case too the distances
between the tube
rows and the tube layers of the register would be identical at every point of
the register. Also
the register then has a symmetrical structure.
In a tube bundle of a register of a heat exchanger with a triangular
distribution, which
is illustrated in Fig. 1 b, the tube layers RL' are not aligned flush with one
another, but are
displaced with respect to one another by in each case half a tube
interspacing. At every
point within the register there are adjacently located three tubes R', whose
mid-points lie at
the vertices of a triangle and whose side edges have the same length b. This
is therefore an
equilateral distribution. The sides of a corresponding triangle defining the
distribution could
however also be of different lengths. In this case too all tube mid-points of
corresponding
adjacent tubes would however in each case define equal triangles. This means
that registers
constructed in this way are also symmetrical throughout.
The tubes R, R' in both a triangular distribution and in a square distribution
form flow
channels with a constant width. The displacement of the tube layers RL' with
respect to one
another means however that the tubes R' in a triangular distribution can be
more tightly
packed than the tubes R in a square distribution, without the pressure loss
rising unduly. In
the end an extremely symmetrical arrangement of the tubes R, R' within the
register of a heat
exchanger is obtained both in a square distribution as well as in a triangular
distribution. This
means that the distribution, i.e. the tube interspacings a, b, in each section
of the register of a
heat exchanger are identical. Consequently there exist neither flow channels
of different
channel width nor flow channels that have a wide section and a narrow section.
Fig. 2 shows a detail of a heat exchanger 1 that comprises a register 2 with
tubes 3
aligned parallel to one another. As is illustrated for example in Fig. 3 in a
horizontal section
CA 02780585 2013-12-10
along the plane 11-ll of Fig. 2, the register 2 has perpendicular to the flow
direction S of the
utility fluid a row of tube rows 4 arranged behind one another, which in the
flow direction S of
the utility fluid form tube layers 5 arranged parallel to one another. The
individual tubes 3 of
each tube layer 5 are arranged flush behind one another in the flow direction
S of the utility
fluid.
In the illustrated register 2 in each case two adjacent tube layers 5 define
between
them a flow channel 6, 6' for the flow through of the utility fluid. In this
connection each flow
channel 6, 6' in each tube row 4 has a channel width 7, 7' that is fixed by
the interspacing of
in each case adjacent tubes 3. In the case of the register 2 illustrated in
Figs. 2 and 3 the
channel widths 7, 7' of each flow channel 6, 6' are constant in the flow
direction S of the
utility fluid. The channel width 7, 7' of the flow channels 6, 6' therefore
does not change from
tube row 4 to tube row 4 of the register 2. In addition the channel width 7,
7' in the illustrated
embodiment is in each case aligned perpendicular to the flow direction S of
the utility fluid.
In each tube row 4 of the illustrated register 2 flow channels 6, 6' with a
large channel
width 7' and a small channel width 7 alternate. On account of the larger
channel width 7' a
higher flow velocity of the utility fluid is established in the corresponding
flow channels 6',
while on account of the smaller channel width 7 a lower flow velocity of the
utility fluid is
established in the remaining flow channels 6.
The tubes 3 provided in the tube rows 4 illustrated in Figs. 2 and 3 are in
each case
grouped in pairs and are fixed on a common rod-shaped retaining element 8 that
extends
parallel to the adjoining tube layers 5, i.e. in other words along the flow
channel 6 of small
channel width 7. In front of the register 2 the retaining elements 8 are held
in the illustrated
plane of the register 2 on a suspension 9 running transverse to the register.
The retaining
elements 8 have spacers 10, against which abut from two sides two adjacent
tubes 3 of
different tube layers 5. An annular element 11 surrounding the tubes 3 serves
to fix in each
case two adjacent tubes 3 of different tube layers 5 to a retaining element 8.
Through the
grouping in each case of two tube layers 5 to a retaining elements 8, the
retaining elements
in the illustrated register 2 are in each case provided only in every second
flow channel 6.
A further detail of the register 2 according to Figs. 2 and 3 is illustrated
in Fig. 4,
wherein Fig. 4 illustrates a view corresponding to Fig. 2, which however shows
a section in a
region in which rinse lines 12 are provided for flushing and in this way
removing interfering
components from the register 2. For this purpose the rinse lines 12 can be
arranged at
21
CA 02780585 2013-12-10
different heights in the register. In any case, at least some of the rinse
lines 12 are arranged
relatively high in the register 2. In addition the rinse lines 12 are provided
only in every
second flow channel 6. In this connection the rinse lines 12 extend
substantially along the
whole flow channels 6 through the register 2. Furthermore it is possible,
although not shown
In the illustrated register 2 the rinse lines 12 are provided in the narrow
flow channels
6 and also have an external diameter that is substantially the same as the
smaller channel
width 7 of these flow channels 6. In this way the rinse lines 12, which abut
against the
adjacent tubes 3, serve at the same time as spacers 12 for in each case two
adjacent tube
15 As a comparison of Figs. 2 and 4 shows, the channel width 7, 7' of the
respective flow
channel 6, 6' does not vary as regards its height in the illustrated register
2, but remains
constant. This is achieved in particular if the tubes 3 run parallel to one
another.
Fig. 5 shows a register 2' schematically in a section perpendicular to the
longitudinal
length of the tubes 3. In this register the tube layers 5' are not parallel,
but are aligned
The register 22 of a heat exchanger 21 illustrated in Fig. 6 differs from the
register 2
illustrated in Figs. 2 and 3 in that tubes 3, 23 of different diameters are
installed. In this
connection exclusively tubes 3, 23 of identical diameter are provided in each
tube layer 5, 25.
The tube layers 5, 25 are also assembled together to form the register 22 in
such a way that
22
CA 02780585 2013-12-10
these two tube layers 5 and is likewise rod-shaped. This flow channel 6 is in
each case a
flow channel with a constant small channel width 7. On the other hand between
the tube
layer 25 with the tubes 23 with a large diameter and the adjoining tube layer
5 with tubes 3
with a small diameter, there is always a flow channel 26 that has a large
channel width 27.
For economic reasons each tube layer 25 with tubes 23 with a large diameter is
held
by a separate retaining element 28, which is arranged to the side of the tube
layer 25. This
retaining element 28 can therefore also function without separate spacers. The
two in each
case adjacent tube layers 5 with tubes 3 of a smaller diameter are in the
illustrated
embodiment constructed as already described with reference to Figs. 2 to 4.
The same also
applies in principle to the arrangement of the rinse line in the flow channels
6 with a small
channel width 7, in other words the flow channels 6 between the tube layers 5
with tubes 3 of
a small diameter. The register 22 illustrated in Fig. 6 comprises exclusively
rectilinearly
formed tubes 3, 23. However in any case tubes that are to some extent curved
could also be
used to construct the register.
In the register 42 of a heat exchanger 41 illustrated in Fig. 7, similar to
the register 2
illustrated in Fig. 2, simply the front-most tube row 44 is illustrated since
the further tube rows
44 are arranged flush with the front tube row 44.
The special feature of the register 42 illustrated in Fig. 7 compared to the
register 2
according to Figs. 2 to 4 is that the tubes 43 are alternately part of a first
tube layer 45 and a
second tube layer 45' of the common tube row 44. The tubes 43 cross one
another at the
transition from the first tube layer 45 to the second tube layer 45', and vice
versa. A flow
channel 46 with narrow sections 54, i.e. smaller channel widths 47, is formed
between the
corresponding crossing points 53. Individual members of the narrow sections 54
have a
spacer 50 or a flush line 52. In the illustrated embodiment the flush line 52
has the same
external diameter as the spacer 50, so that the flush line 52 holds the two
paired crossed
tubes 43 simultaneously at the desired interspacing from one another.
The illustrated tubes 43 crossed with one another are rigidly designed, so
that means
does not have to be provided in each case between two crossover points 53 of
the tubes 43
that contributes to the interspacing of the tubes 43. When using flexible
tubes such means
would preferably be provided between in each case two adjacent crossing points
of a flow
channel so that the tubes can permanently adopt the desired positions.
The flow channels 46' adjoining the two paired crossed tubes 43 have varying
channel widths 47'. The flow channels 46' are broadest at the height of the
crossing points
23
CA 02780585 2013-12-10
53 and narrowest at the mid-height between the crossing points 53. In this way
the flow
channels 46' adjoining the crossed tubes 43, which channels are bounded by the
adjacent
rectilinearly running tubes 43' of the tube row 44, in turn have narrow
sections 54' and wide
sections 55 alternating over their height.
The crossing of the tubes 43 is accomplished in the embodiment illustrated in
Fig. 7
in the manner of a wickerwork, in which each of the two tubes 43 crossed with
one another is
led alternately in the flow direction S in front of and behind the respective
other tube 43 to the
in each case other tube layer 45, 45'.
However, as in the embodiment of a register 62 of a heat exchanger 61
illustrated in
Fig. 8, this arrangement can if necessary be dispensed with. Instead, the one
tube 63 of the
two tubes 63, 63' crossed with one another is always led in front of the other
tube 63' to the
other tube layer 65, 65'.
With the registers 42, 62 illustrated in Figs. 7 and 8 tubes 43, 63, 63'
crossed paired
with one another and rectilinearly running tubes 43', 63" in a tube row 44,
64, alternate with
one another.
However, with the register 82 of a heat exchanger 81 illustrated in Fig. 9,
all tubes 83
of a tube row 84 are in each crossed paired with one another, and more
specifically in each
case multiply over the longitudinal length of the tubes 83. In this case
always the same
tubes 83 are crossed with one another. In principle however tubes alternating
with different
tubes, preferably of different tube layers, could also be crossed with one
another. Likewise,
it is not essential that simply tubes 83 of adjacent tube layers 85 are
crossed with one
another and/or that the tubes 83 crossed one another always belong to the same
tube row
84. The tubes 83 are crossed with one another in a wickerwork arrangement.
The register 82 illustrated in Fig. 9 has exclusively paired crossed tubes 83.
The
crossing points 93 of the in each case paired crossed tubes 83 in any case of
one tube row
84 lie in common planes 96 parallel to the flow direction. In this way wide
sections 95 and
narrow sections 94 therebetween are provided in the flow channels 86 between
the paired
crossed tubes 83 in the region of the crossing points 93, so that the channel
widths 87, 87'
vary over the longitudinal length of the flow channels 86. The paired crossed
tubes 83 define
between them in each case a flow channel 86', which has exclusively narrow
sections 94'
with smaller channel widths 87", though these do not have to be identical to
the narrow
sections 94' of the in each case adjacent flow channels 86.
24
CA 02780585 2013-12-10
With regard to the spacers 90 and rinse lines 92 provided if necessary in the
flow
channels 86' defined by the paired crossed tubes 83, the same is true as has
already been
said concerning the heat exchanger 41 illustrated in Fig. 7.
In a non-illustrated embodiment of a register with in each case paired crossed
tubes,
the crossing points of adjacent tubes in each case crossed with one another
could also lie on
different planes. For example, only every second crossing point in the
direction of a tube row
lies in one of these planes. Preferably in each case the crossing points of
two tubes crossed
with one another looking in the longitudinal direction of the tubes and/or of
the register lies
substantially, in particular centrally, between the crossing points of the
adjacent tubes
crossed with one another, in particular on both sides of the tube row. The
crossing points of
these adjacent in each case paired crossed tubes on both sides of the tube row
then
preferably lie on common planes, in particular also with the crossing points
of the in each
case next but one paired crossed tubes of the at least one tube row.
A corresponding arrangement has the result that the flow channel between in
each
case two paired crossed tubes has a relatively uniform channel width over the
flow channel
height. According to a corresponding embodiment the corresponding flow channel
would
assume a substantially sinuous shape.
The floor region of heat exchanger 101 with U-shaped tubes 103 is illustrated
in Fig.
10. The U-shaped tubes 103 of the register 102 are suspended in the heat
exchanger 101 in
the direction of gravity, so that the tube curvatures 117 of the U-shaped
tubes 103 point in
the direction of the floor 118 of the heat exchanger 101. A gap 119, through
which the utility
fluid can flow, remains between the bent tubes 103 and the floor 118 of the
heat exchanger
101. In the region of the tube curvatures 117 there is installed in the flow
direction S of the
utility fluid in front of the tubes 103 of the register 102 an in this case
plate-shaped barrier
120, which in the illustrated embodiment extends in a plane perpendicular to
the flow
direction S of the utility fluid. In this connection the barrier 120 is
arranged so that a gap 119
is formed between the floor 118 of the heat exchanger 101 and the lower edge
121 of the
barrier 120, through which the utility fluid flows with increased velocity and
in the floor region
entrains deposited interfering components, such as for example particles,
without at the
same time causing an increased abrasion of the register 102 in the region of
the tube
curvatures 117. This increased flow velocity of the utility fluid in the gas
122 underneath the
tube curvatures 117 is illustrated diagrammatically in the sectional view of
Fig. 11.
CA 02780585 2013-12-10
. .
As a result of the build-up of the utility fluid in the flow direction S in
front of the barrier
120, increased flow velocities are likewise produced when the utility fluid
overflows the
barrier 120, so that the utility fluid flows with increased flow velocity
through the region of the
tube curvatures 117 and there removes interfering components that have sunk
down from
above from the flow of the utility fluid. In addition the flow channels with
large channel widths
can be widened in the region of the lower end of the register, where the tube
curvatures are
located, as a result of which the flow channels with small channel widths
become locally
narrower. This can have a positive effect in transporting the interfering
components away
from the register.
26
